Five people were shot on Tuesday in an attack at a school for adults in Sweden, police said, but they declined to comment on local media reports that several people had been killed.
The perpetrator is believed to be among those injured and a search is continuing at the school for more possible victims, a police spokesperson told a news conference. The perpetrator's motive was not immediately known.
"This is currently seen as attempted murder, arson and aggravated weapons offence," police said in a statement, adding that the extent of the injuries of the five people who had been shot remained unclear.
The shooting took place in Orebro, some 200 km (125 miles) west of Stockholm, at the Risbergska school for adults who did not complete their formal education or failed to get the grades to continue to higher education. It is located on a campus that also houses schools for children.
Maria Pegado, 54, a teacher at the school, said someone threw open the door to her classroom just after lunch break and shouted to everyone to get out.
"I took all my 15 students out into the hallway and we started running," she told Reuters by phone. "Then I heard two shots but we made it out. We were close to the school entrance."
"I saw people dragging injured out, first one, then another. I realised it was very serious," she said.
No police officers were injured in the shooting, police said. Ambulances, rescue services and police were at the scene, a spokesperson for local rescue services said.
Police said students were held indoors at the school that was targeted and at other schools nearby.
Sweden's Justice Minister Gunnar Strommer told Reuters the government was in close contact with the police and was following developments closely.
"The information about the violent attack in Orebro is extremely serious," he said.
Sweden has been struggling with a wave of shootings and bombings caused by an endemic gang crime problem, though fatal attacks at schools are still rare.
Ten people were killed in seven incidents of deadly violence at schools between 2010 and 2022 according to the Swedish National Council for Crime Prevention.
In one of the highest profile such crimes in the past decade, a 21-year old masked assailant driven by racist motives killed a teaching assistant and a boy while wounding two others in 2015.